Comware

Hello,

I have a question about the Comware command: display packet-drop

As the HPE documentation says, this command displays "information about packets dropped on an interface or multiple interfaces"  (source : https://support.hpe.com/hpsc/doc/public/display?docId=c04904833, page 17), and the field "Packets dropped due to full GBP or insufficient bandwidth"  in the output of this command means "packets that are dropped because the buffer is used up or the bandwidth is insufficient".

Here is an example of the output of this command:

<SWITCH>dis packet-drop interface GigabitEthernet1/0/1
GigabitEthernet1/0/1:
  Packets dropped by GBP full or insufficient bandwidth: 2868
  Packets dropped by FFP: 90271666
  Packets dropped by STP non-forwarding state: 0

This example tells us that there were 2868 packets dropped because of a saturated port or saturated buffer. But what are exactly these 2868 packets?

1 - Packets that were arriving ingress on G1/0/1 and going to another port but which was saturated and with the buffer pool full too => no room left, so the packets had to be dropped

2 - Packets that were arriving ingress on a port different from G1/0/1 and trying to exit via G1/0/1, but G1/0/1 was saturated and the buffer pool too => no room left, so the packets had to be dropped.

3 - It can be a mix of 1- and 2-

Thanks a lot in advance for clarifying this!

Hi,

Here 2868 are the number of packets dropped due to insufficient port buffer.

Many times when user has a large volume of multicast traffic that switch to duplicate to many ports. But in many cases there are no sufficient port buffer to handle the traffic.
Globally enabling burst mode helps to solve the problem.

Thanks!

Hello,

Thanks for your reply but you did not answer the question.
I know that 2868 is the number of packets that were dropped because of insufficient port buffer.
Please read my question carefully, I wanted to know where these packets were dropped (ingress or egress the switch).

Thanks.

Hi,

As per your statement, packet will be dropped at both ingress & egress.

Thanks !